You can check the location of your Outlook Data Exchange connectivity diagnostic Files in Outlook.

Repair Outlook Data Files (.pst and .ost)

If you're using an Exchange email account, you can delete the offline Outlook Data File (.ost) and Outlook will recreate the offline Outlook Data File (.ost) the next time you open Outlook. Even with the reg hack in place, I’ve found that ost files over 50gb tend to corrupt and become unusable with regularity. OST file corruption is a common problem faced by Outlook users like you. While you seek to counter this problem, you look for effective techniques. Although there are many methods to try, a few are productive.

Outlook - OST file recurring corruption

Although the repair process might recreate some of the folders, they may be empty. The FixTechGuide support for Office 365 Lost and Found folder contains any folders and items recovered by the repair tool that Outlook can't place in their original structure. You can use the Inbox Repair tool (SCANPST.EXE) to diagnose and repair errors in your Outlook data file.

• The Inbox Repair tool checks the Outlook data files on your computer to see if they're in good shape.
• You can try syncing outlook file 6 to 12 months or through archiving email using retention policy, could be a better way to protect the .ost size from corrupt.
• The Inbox Repair tool creates a backup file with the same name as the original, but with a .bak extension, and saves it in the same folder.
• The file would get inaccessible and won't update in any case.
• We will help our readers decide the best way to rebuild OST for functioning through Outlook.
• You can use the Inbox Repair tool (SCANPST.EXE) to diagnose and repair errors in your Outlook data file.

What are the major Reasons of OST Corruption and how to Fix it

When Outlook is running and is halted in such a way, it can damage the OST file. You might be working on something important across it when it happens. As you said Outlook E3 licenses should support at least 100GB of data & there’s no excuse why it can’t support OSTs above 50GB when they offer twice that space. In addition, you could open outlook in safe mode, maybe some add-ins affect the outlook. You could Right-click the Start button, and click Run, type Outlook.exe /safe, and click OK. Refer to this blog Solutions To Fix Error – "Errors Have Been Detected In The File Xxx.Ost" Solutions To Fix Error – "Errors Have Been Detected In The File Xxx.Ost" for the solution to this OST error.

Method 4: Use OST Repair Tool

This article offers to rebuild the OST file without putting you in any difficulty. While this is an effective model, the discussion would revolve around all possibilities. We will help our readers decide the best way to rebuild OST for functioning through Outlook. reset cached Exchange mode For the past 2 weeks, the OST of my Desktop Outlook has been corrupting continuously. I have 2 computers and both have been facing the same issue.